Why TripAdvisor's Shares Plunged

Is this meaningful? Or just another movement?

Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of travel website operator TripAdvisor(Nasdaq: TRIP) sent investors packing today, as they fell 17% after the company reported second-quarter earnings.

So what: For the quarter, TripAdvisor's total revenue clocked in at $197 million, up 16% from the year before, while earnings per share were $0.41. The company's per-share profit matched analysts' expectations, but revenue fell short of the $204 million average estimate. In particular, the company's international growth slowed markedly, while the revenue contribution from its former parent, Expedia(Nasdaq: EXPE), declined.

Now what: Investors seem to be taking the results from TripAdvisor as a sign of things to come from other Internet travel companies -- shares of both Expedia and priceline.com(Nasdaq: PCLN) were also down on the day. And for the TripAdvisor shareholders looking for the good news from the quarter? Though financial performance may not have been stellar, the TripAdvisor community continues to grow, as the company said its current 32 million marketable members is a 25% increase from the March quarter.